Let's say we have nvm installed in a separate mount, /.socket. NVM_DIR is $HOME/.nvm in /etc/profile.d/nvm.sh. With this setup, users can install Node versions to their home directories without each installing nvm.
nvm install --lts
This works fine as does nvm use --lts. When nvm exec is used though, it fails because it looks for nvm-exec in $NVM_DIR. First fix is to look for nvm-exec in $NVM_DIR. If NVM_DIR does not contain nvm-exec, check $BASH_SOURCE[0]. The second fix is to follow nvm-exec if a symbolic link to determine the proper location of nvm's home. Alternatively we could use a second environment variable, NVM_HOME in exec instead of relying on the directory name of nvm-exec.
Path lists in environmental variables often give special meaning to
empty entries (e.g. in PATH or MANPATH). These are represented by
leading or trailing colons, or by doubled colons in the middle of the
list.
Adjust the awk invocation to correctly deal with trailing colons by
printing the separator before every field except the first, and then
printing the final separator that is read from the input - this will
either be a colon or the null string. This preserves leading and
trailing colons in all cases while not adding extra colons in the wrong
place.
Add test to confirm the correct behaviour.
Fixes#3144
I had to dig into #2410 to learn about the `PROFILE=/dev/null` technique to install without appending to my shell config. Figured this note would be good to add in the main installation docs.
Also added a note on how to do this as a one-liner which was not obvious for me.
the `nvm.sh` file assigns and exports an `NVM_CD_FLAGS` variable if it
was sourced from a zsh shell. the fact that it's exported means that
it'll be assigned in all child processes, including the `nvm-exec`
script, which uses bash as the interpreter.
Bash's `cd` command doesn't have a `-q` flag, so if the `NVM_CD_FLAGS`
is assigned `-q`, the script will error out and incorrectly claim that
the node version isn't installed.
this also manifests itself in the `nvm exec` command.
Example:
```console
$ nvm exec 16.14.0 npm --version
Running node v16.14.0 (npm v8.3.1)
/Users/<ME>/.nvm/nvm.sh: line 28: cd: -q: invalid option
cd: usage: cd [-L|[-P [-e]] [-@]] [dir]
both the tree and the node path are required
N/A: version "v16.14.0 -> N/A" is not yet installed.
You need to run "nvm install v16.14.0" to install it before using it.
```
To address this, we unset the `NVM_CD_FLAGS` at the start of the
`nvm-exec` script, before loading `nvm.sh`.
